Stillwater County Bridge Report Card

Stillwater County scores 92 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

A92 / 100

Local infrastructure snapshot

Stillwater County, Montana

Stillwater County has 92 bridges in the National Bridge Inventory, with 1 rated poor and 2 rated scour-critical. Its poor-condition share of 1.1% is at or below the 7.4% statewide average. Poor-condition bridges carry about 5,017 daily vehicle crossings.

92Total Bridges

1Poor (1.1%)

63Fair (68.5%)

2Scour-Critical

Quote-Ready Local Facts

1.1%of county bridges are in poor condition, compared with 7.4% statewide and 6.7% nationally.

5,017daily vehicle crossings are on poor-condition bridges in the county.

2bridges are rated scour-critical, or 2.2% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Stillwater County a Bridge Condition Exposure Score of 92/100 (A). The county has 92 bridges in the National Bridge Inventory, including 1 in poor condition and 2 rated scour-critical. Poor-condition bridges carry about 5,017 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	1.1%	2.2
Poor-condition traffic exposure	25	1.8% of measured traffic	1.4
Scour-critical bridge share	20	2.2%	4.3
Average age vs national baseline	10	49 years vs 48 nationally	0.4
Traffic-data completeness	5	274,042 measured daily crossings	0.0

Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.

County Comparisons

County Poor-Condition Share	1.1%
State Poor-Condition Share	7.4%
National Poor-Condition Share	6.7%
County Scour-Critical Share	2.2%
Average Bridge Age	49 years
Poor-Condition Traffic Exposure	5,017 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeS 78 over Yellowstone River — 5,017 vehicles/day Oldest Listed BridgeOld US 10 over Big Ditch 010 — built in 1928 All County BridgesBrowse every bridge record in Stillwater County.

Top Bridges to Watch in Stillwater County

Bridge	Reason	Condition	Daily Traffic	Year Built
S 78 over Yellowstone River	Poor condition + traffic exposure	Poor	5,017	1957
W Grove ST over Rosebud Creek	Scour-critical foundation rating	Good	507	1989
I 90 over Cove Irrigation Ditch	High traffic	Good	12,321	1970
I 90 over Int Exit 396	High traffic	Fair	10,845	1963
I 90 over Int Park City	High traffic	Fair	7,580	1967
I 90 over Int Park City	High traffic	Fair	7,580	1967
I 90 over Sep Pope Road	High traffic	Fair	7,580	1967
I 90 over Sep Pope Road	High traffic	Fair	7,580	1967
I 90 over Hensley Cr-hensley CR RD	High traffic	Fair	6,161	1970
I 90 over Hensley Cr-hensley CR RD	High traffic	Fair	6,161	1970

Important safety note

Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.